Skip to main content

Reply to this post | See parent post | Go Back
View Post [edit]

Poster: Dhamma1 Date: May 18, 2011 5:38am
Forum: GratefulDead Subject: Re: Recording, tapes, sound quality... 101?

Hmm... Think about digital photos. Assuming you have a digital camera, you can set it to take pictures that turn out really really big and you can blow them up or zoom in on them and everything remains clear; but you can't fit too many on your camera or memory card. You can also take smaller pictures that quickly get all fuzzy if you blow them up or zoom in on your computer. Audio files work sort of the same way.

The music here started out on magnetic tapes of various kinds (cassettes, reels, etc). Tapes recorded by the band at the mixing board where they controlled the sound in the hall at the time of the show are called soundboards (SBD) and contain little if any audience noise. They can vary in sound quality according to how the mix was done at the time of the show; sometimes people plugged into the SBD to make their own tapes (sometimes stealthily); sometimes the SBD was broadcast on an FM radio station and the signal was captured before it left the hall.

Audience tapes (AUD), in contrast, were made by a listener who carried recording equipment into the venue and held a microphone up in the air. Sometimes this was tolerated or even encouraged by the band and promoters, but sometimes it had to be done secretly. Sound quality therefore varies tremendously. Both SBDs and AUDs started out as magnetic tapes. Beginning about 1980 (I think), a tape was invented that recorded for computers instead of tape recorders -- digital audio tape (DAT).

During the 1990s and continuing to this day, those historic tapes were converted to digital formats. Usually a "lossless" digital audio file was made, which corresponds to that enormous digital photo we started with, above. Then these could be compressed so they take up much less memory. During compression, however, much of the data is usually lost. With photos, TIF is a very large high-resolution format and JPG and PDF are examples of compressed formats. With audio, WAV is an example of lossless and MP3 of compressed.

Listeners with great ears and expensive systems usually prefer lossless audio files. Most people listening on a cheap stereo or iPod can't tell the difference between MP3 and lossless, and opt for the smaller compressed files.

The different versions of a show that are available to us here reflect all these variables. AUD and SBD denote how the original recording was made; the source and lineage statements for each show document all the steps performed between then and the specific file offered on that specific page of the site. Some tapers did a better job than others (Betty Cantor and Bear at the SBD), some editors who converted to digital did a better job than others (Charlie Miller is probably the most respected here). Some editors such as Hunter Seamons blend AUDs and SBDs together to make what is called a Matrix; some people like them and some think they're inauthentic.

There is much more information about this in the long forewords and interviews contained in the three volumes of the Grateful Dead Taping Compendium. Go to the nearest public library and ask the staff to get these for you through interlibrary loan, or look for them at abebooks.com, since they're virtually unobtainable now. In them, many of the people who captured, converted, preserved, and shared this music speak about how they did it.

Now: everybody else, please step up and correct my errors and omissions.

Cheers,

- Michael

Reply to this post
Reply [edit]

Poster: wisconsindead Date: May 18, 2011 8:58am
Forum: GratefulDead Subject: Re: Recording, tapes, sound quality... 101?

Cool thanks guys. That does clear up a few things. I was into the matrix's (or matrices?) for a while but i typically just prefer SBD. Though I do like 1971-12-01 AUD.

Another thing I am confused with is the speed of recording. I've seen people mention things like 24/96 reel speed or something like that. What makes the difference when it comes to speed?

thanks for the links, book suggestions and info peeps.

Reply to this post
Reply [edit]

Poster: Germain Date: May 19, 2011 7:03am
Forum: GratefulDead Subject: Re: Recording, tapes, sound quality... 101?

Duckpond74 did an excellent job of describing how tape speed influences the quality of the recording. One thing he failed to mention was the tracking method the taper employed. This is important because the width of the tracks on the tape also affects audio quality. While professional studios might use 1 inch or wider tape, the standard reel used 1/2 inch tapes. One could record in only one direction and use half the tape width for each channel or the tape could be recorded in both directions using 1/4 the width for each channel. Most people used quarter track to conserve tape, but everything else being equal, a half track tape is a superior recording.

Not many tapers lugged reel to reel decks to shows, so the digitized reel recordings in circulation come mostly from tapes recorded by the band. By the late 70's - early 80's the band had switched to using cassettes to record the shows. This was not as a big a drop off recording quality as it might seem, because by that point the technology of high end cassette decks had greatly improved. The drop off in quality of the early & mid 80's soundboards can be attributed to the different mix that was being used rather than the recording equipment. The earlier reels were recorded for playback purposes and were not recordings of the house mix. Most of the later cassette recordings were from the PA mix. The PA mix was balanced to optimize the sound in the hall, stadium or what have you, but was not the most ideal for later playback.

The 24/96 you mention refers to the digitization parameters the person used when transferring the audio off the tape. The numbers refer to the sample rate and bits used at each sample to capture to audio. In this case the 96 indicates 96,000 samples of the analog signal were taken per second and 24 bits were used to capture the level of the signal at each sample. 24 bits = 2^24 = 16,777,216 voltage levels which are available to select from at each sample point. So in effect, the more samples taken and the more bits used, the closer the digital recording comes to the analog signal.

Most people use 24/96 when transferring into the digital realm then down sample to 16/44.1 (the CD standard) before circulating the recording. Unless the analog recording was of a very high quality low generation reel, using 96k is not going to improve the sound quality.

Using 24 bits will often add additional clarity and allow one to hear the subtle nuances of the music of a high quality analog recording. Most often the difference is not very dramatic though. The difference between 16 & 24 bits is similar to an artist having approximately 65,000 colors on his palate to have 16 million. Sounds like a a big difference, but the variance between shades when using 65,000 colors is almost indistinguishable, bumping the palate up to 16 million shades isn't going to make that much difference.

Reply to this post
Reply [edit]

Poster: duckpond74 Date: May 18, 2011 11:14am
Forum: GratefulDead Subject: Re: Recording, tapes, sound quality... 101?

"Another thing I am confused with is the speed of recording. I've seen people mention things like 24/96 reel speed or something like that. What makes the difference when it comes to speed?"

I can't speak to the 24/96 digital bits, but to answer your question on analog taping speeds, "It's the space between the sounds is where the beauty lies ..."

The faster the speed - 30 ips, or "inches per second", is for your studio needs. Maximum speed collects maximum sound. 15 ips on 10 1/2 inch reels is also used by many studios, and the professional "live" recording folks, like in-studio live radio recording of sessions, and remote 'traveling studios' like the impressive Record Plant truck of the late 70's (I'm sure there are plenty of other examples out there).

7 1/2 ips was the high-end standard for most home recorders. And 3 3/4 ips was the common speed for those that were on a budget, or wanted to be able to record longer uninterrupted pieces without a tape flip - you would get twice as much tape / time per side at the lower speed, thus often eliminating the need, in most cases, to flip the reel during a set or extended jam. The downside being, the slower the speed, the lesser quality recording - "It's the space between the sounds", or even notes, that dictates the amount of sound and, thus the quality of the overall ambient recording that will be reproduced later. Cassettes are almost always recorded at 1 7/8 ips - a "huge" and noticeable difference from tapes recorded at 7 1/2 ips on up.

I listen to a lot of music on reels that was recorded decades ago. Interesting enough, the speed has also dictated how many of these recordings have held up over time. My commercial pre-recorded reels at 7 1/2 still sound crisp and sharp, and the bass is full and rich, whereas the commercial recordings at 3 3/4 (many bought through the 'Columbia Reel Of The Month Club') have not aged nearly as well. They sound comparatively distant and flat for the most part, devoid of much of the sonic depth and aural excitement that reels are known for.

Much of the early Dead stuff was recorded on Scotch 3M 150 or 201 - a tape that did not age too well as a medium. Many of us taping heads ran with their example at the time, and now have varying degrees of quality recordings. I recorded several artists in the seventies and eighties on reels - from Steve Goodman and Muddy Waters to Jethro Tull and John Cage - from bluegrass and folk, to blues and jazz, to rock, classical and experimental - as well as many Grateful Dead radio broadcasts and tape trades. Everything I recorded back then on Maxell 35-90 still sounds fresh and fantastic today. Money well spent at the time.

So, Wisconsindead, I hope that answers your question, at least on the analog front. I could discuss at-length about the benefits and quality of analog recording versus digital recording, but I'll pass on that for now. Suffice to say, "it's the space between the sounds and notes which make the listening experience that much richer" . . . 7 1/2 inches is so much more substance than 1 7/8 inches, and 15 and 30 inches can be immense in terms of 'collecting the information'.

Reply to this post
Reply [edit]

Poster: dead-head_Monte Date: May 18, 2011 8:52am
Forum: GratefulDead Subject: Re: Recording, tapes, sound quality... 101?

Reviewer: dead-head_Monte - 5.00 out of 5 stars5.00 out of 5 stars5.00 out of 5 stars5.00 out of 5 stars5.00 out of 5 stars - May 18, 2011
Subject: Dhamma makes some good points

• take a look at my funky Taper's Handbook

Monte's Taper Handbook for The Internet Archive